In an orthogonal frequency division multiplexing (OFDMA)-based cellular radio interface, such as described in patent application Ser. No. 11/907,808, by Sassan Ahmadi and Hujun Yin, filed on Oct. 12, 2007, which is herein incorporated by reference in its entirety, propagation of radio signals in large cell sizes and/or lower frequency bands can lead to larger delay spread and consequently can cause inter-symbol interference (ISI) effects in the received signals. In the OFDM-based systems, the effects of ISI are mitigated by the cyclic prefix that is added to the beginning of the OFDM symbols. The larger the delay spread, the longer the cyclic prefix should be used to alleviate the ISI effects.
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